Oh! Just realized - I totally overlooked that. You're totally right, it would be UB under the current rules - could just add a special case for char, unsigned char and std::byte.Sent from my Samsung Galaxy smartphone.
-------- Original message --------From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]> Date: 8/17/19 20:12 (GMT-05:00) To: std-proposals_at_[hidden] Cc: Language Lawyer <language.lawyer_at_[hidden]> Subject: Re: [std-proposals] Allowing access to object representations ok, never mind...On 18/08/2019 03:06, sdkrystian via Std-Proposals wrote:> Yes, since the object representation is considered to be an array containing the elements of the object representations.> > > > Sent from my Samsung Galaxy smartphone.> > -------- Original message --------> From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>> Date: 8/17/19 20:04 (GMT-05:00)> To: std-proposals_at_[hidden]> Cc: Language Lawyer <language.lawyer_at_[hidden]>> Subject: Re: [std-proposals] Allowing access to object representations> > On 18/08/2019 03:02, sdkrystian via Std-Proposals wrote:> > That has no effect, the array is an array of unsigned char objects, so a pointer arithmetic applied to a element of it is well within the rules.> > Using a pointer of type "pointer to char" to do arithmetic would be well within the rules?> > > Sent from my Samsung Galaxy smartphone.> >> > -------- Original message --------> > From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>> > Date: 8/17/19 19:59 (GMT-05:00)> > To: std-proposals_at_[hidden]> > Cc: Language Lawyer <language.lawyer_at_[hidden]>> > Subject: Re: [std-proposals] Allowing access to object representations> >> > https://timsong-cpp.github.io/cppwp/n4659/expr.add#6> >> > On 18/08/2019 02:49, sdkrystian via Std-Proposals wrote:> > > unsigned char.> > >> > >> > >> > > Sent from my Samsung Galaxy smartphone.> > >> > > -------- Original message --------> > > From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>> > > Date: 8/17/19 19:46 (GMT-05:00)> > > To: std-proposals_at_[hidden]> > > Cc: Language Lawyer <language.lawyer_at_[hidden]>> > > Subject: Re: [std-proposals] Allowing access to object representations> > >> > > On 18/08/2019 02:42, sdkrystian via Std-Proposals wrote:> > > > You're right, there wouldn't be unless I specified that the object representation is considered to be an array> > >> > > Array of which type???> > >> > > > Sent from my Samsung Galaxy smartphone.> > > >> > > > -------- Original message --------> > > > From: Language Lawyer via Std-Proposals <std-proposals_at_[hidden]>> > > > Date: 8/17/19 18:58 (GMT-05:00)> > > > To: std-proposals_at_[hidden]> > > > Cc: Language Lawyer <language.lawyer_at_[hidden]>> > > > Subject: Re: [std-proposals] Allowing access to object representations>  >  >  >>  >  >  > You propose:>  >  >  >  > Insert a new paragraph below [expr.reinterpret.cast] p6> > > > > A prvalue v of object pointer type "pointer to cv1 T1" pointing to an object a can be explicitly converted to an object pointer of a different type "pointer to cv2 T2", where cv2 is the same cv-qualification as, or greater cv-qualification than cv1, the result of which is defined as follows:> > > > > — f T1 is a contiguous-layout type and T2 is unsigned char, char or std::byte, the result is a pointer to the first element of the object representation of a.> > > >> > > > Is there much sense in specifying casts to `char` or `std::byte` as giving a pointer to the first element of the object representation?> > > > You won't be able to use it for pointer arithmetic.> > > > --> > > > Std-Proposals mailing list> > > > Std-Proposals_at_[hidden]> > > > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals> > > >> > > --> > > Std-Proposals mailing list> > > Std-Proposals_at_[hidden]> > > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals> > >> > --> > Std-Proposals mailing list> > Std-Proposals_at_[hidden]> > https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals> >> -- > Std-Proposals mailing list> Std-Proposals_at_[hidden]> https://lists.isocpp.org/mailman/listinfo.cgi/std-proposals> -- Std-Proposals mailing listStd-Proposals_at_[hidden]://lists.isocpp.org/mailman/listinfo.cgi/std-proposals